Background: Low back pain is a significant and growing problem in Veterans. It is especially prevalent in returning Veterans. Among returning Veterans who have disabling pain, it is the most frequent site of their pain. Magnetic Resonance Imaging (MRI) conducted early in an episode of uncomplicated low back pain is not helpful and may lead to unneeded surgeries and medical procedures, greater use of pain medications, and poor outcomes. The percentage of orders for MRI of the lumbar spine that are inappropriate in VA is similar to what has been observed in Medicare and commercial insurance claims. The VA Choosing Wisely Committee and VA national program offices for pain, diagnostic services, and utilization management are working to reduce rates of inappropriate LS-MRI imaging in VA. Attempts to implement guidelines for advanced imaging with decision support tools have generally had modest, short-term effects. Guideline dissemination and audit and feedback have not been effective in improving compliance with guidelines for treatment of low-back pain. New understanding of the barriers and facilitators to guideline adherence is needed to design an effective implementation effort. Inappropriate low back scans are associated with downstream costs from low value treatments for back pain, but this has not been studied in VA. Objectives: National data on new episodes of uncomplicated low-back pain will be studied to identify providers who consistently order a large number of inappropriate scans. Qualitative interviews with a small number of providers will identify differences between providers who are highly concordant with guidelines and those that are less than concordant. The interviews will identify potential modifiable factors that can be the basis of a program to reduce inappropriate ordering. VA utilization data will evaluate the association of inappropriate LS-MRI orders with patient pain, and high-cost, potentially low value services: spinal fusion, laminectomy, epidural injections, and prescription opiates. Methods: The appropriateness of LS-MRI orders will be evaluated over 3 years using national VA administrative data in order to identify a potential focus for implementation efforts: a consistent group of providers that orders a high number of inappropriate scans, and/or particular services or sites where inappropriate ordering is common. A qualitative assessment of a small number of these providers (and a comparison group of providers that follow guidelines) will be conducted to identify potential modifiable factors associated with inappropriate ordering, such as routine order sets, lack of knowledge of guidelines, beliefs about the value of scans, knowledge and availability of care for patients with pain of the lumbar spine. Finally, the effect of inappropriate orders on outcomes, care, and cost will be studied. A cohort of new cases of uncomplicated low-back pain will be identified. Episodes in which LS-MRI is provided in the first 6 weeks will be compared to other episodes to see if there are any differences in patient reported pain, cost, or the use of low-back procedures. These will include spinal fusion, laminectomy, epidural injections, and opioid prescriptions for pain. Since the scans are not randomly assigned, several methods will be used to provide an unbiased assessment of their effect. An areas analysis will determine if geographic locations where many early scans are provided have different outcomes or different rates of procedures. The propensity weighting and instrumental variables methods will also be used to make sure that study finding are not the confounded by the non-random assignment of early MRI. The study will be advised by two national experts on low-back pain and a committee of VA clinicians engaged in implementing guidelines for low back pain and imaging appropriateness.